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Nov 01, 2016

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CardioSource WorldNews | Bypassing Obesity: Should there be a STAMPEDE
to More Bariatric Surgery

Obesity and diabetes appear to be the major drivers of cardiovascular disease and, in particular, coronary artery disease. Current medical based therapies for these conditions are not effective for everybody.

While bariatric surgery is still discussed as a means of achieving weight loss among the chronically – and usually morbidly – obese, the conversation has shifted to thinking of it more as metabolic surgery or “comorbid condition resolution.” Plus, there is increasing emphasis on considering this approach a little earlier.

This effort has been reinforced by the STAMPEDE trial (Surgical Therapy And Medications Potentially Eradicate Diabetes Efficiently).1 This randomized, controlled, single-center study compared intensive medical therapy with optimal therapy plus surgical treatment as a means of improving glycemic control in obese patients with type 2 diabetes.

Investigators screened 218 patients at the Cleveland Clinic and assigned 150 eligible patients to undergo intensive medical therapy alone or intensive medical therapy plus either Roux-en-Y gastric bypass or sleeve gastrectomy. Bariatric procedures were performed laparoscopically by a single surgeon. Gastric bypass consisted of the creation of a 15-to-20 mL gastric pouch, a 150 cm Roux limb, and a 50 cm biliopancreatic limb. Sleeve gastrectomy involved a gastric-volume reduction of 75% to 80% by resecting the stomach alongside a 30-French endoscope beginning 3 cm from the pylorus and ending at the angle of His.

In medical terms, morbid obesity is usually described as a body mass index (BMI) of 40, or 35 to 40 with significant medical issues caused by or exacerbated by weight. A BMI of 40 amounts to approximately 100 pounds above ideal weight. The study population had moderate to severe obesity (BMI > 30 kg/m2) and relatively advanced, poorly controlled diabetes, including many patients with diabetes-related coexisting illnesses or evidence of end-organ damage. Patients had an average disease duration of more than 8 years and a mean baseline glycated hemoglobin (HbA1c) level of 8.9% to 9.5%. At baseline, study participants were receiving, on average, nearly 3 antidiabetic agents, including a relatively high use of insulin (44% of patients) or other injectable therapies (14%).

STAMPEDE Runs to 5 Years

The primary endpoint was the proportion of patients with an HbA1c level of 6% or less (with or without diabetes medications) 12 months after randomization. (Average baseline level was 9.2 ± 1.5%.) Patients undergoing surgery were significantly more likely to achieve a glycated hemoglobin level of ≤ 6.0% 1 year after randomization than patients receiving intensive medical therapy alone.

The primary endpoint, HbA1c ≤ 6%, was achieved in 5% of intensive medical therapy patients, 37% of gastric bypass patients, and 24% of sleeve gastrectomy patients. Nearly all gastric bypass patients who achieved the primary endpoint target did so without requiring any diabetic medications (oral or injectable) while 20% of sleeve gastrectomy patients achieved target without medications.

Patients in the surgical groups had greater mean percentage reductions in weight from baseline, with reductions of 24.5 ± 9.1% in the gastric bypass group and 21.1 ± 8.9% in the laparoscopic sleeve gastrectomy group versus a reduction of 4.2 ± 8.3% in the medical therapy group (p < 0.001 for both comparisons). Quality-of-life (QOL) measures were not evaluated at 1-year follow-up, but were added to the 3-year results. Investigators reported significantly better QOL in the 2 surgical groups than in the medical therapy group, with the greatest improvement seen in the gastric bypass patients. There were no major late surgical complications.

Now, final 5-year data have been reported (TABLE) suggesting superior results with surgery and the curves continue to widen over time in support of surgical intervention. In brief:

More than 88% of gastric bypass and sleeve gastrectomy patients maintained healthy blood glucose levels without the use of insulin.

29% of gastric bypass patients and 23% of sleeve gastrectomy patients achieved and maintained normal blood glucose levels, compared to just 5% of those on medication alone.

Weight loss was significantly greater with gastric bypass and sleeve gastrectomy than with medications and was the primary driver for glucose control.

The effects of both surgical procedures to normalize glucose levels did, however, diminish over time with some late complications noted with surgery.

There were no late major complications of surgery except for one reoperation (a successful laparoscopic conversion of sleeve gastrectomy to gastric bypass for recurrent gastric fistula) that occurred 4 years after randomization.

Significant and durable improvements in bodily pain and general health were demonstrated using a validated QOL instrument in both surgical groups relative to the medical group. Several biomarkers associated with heightened cardiovascular risk were reduced in the surgical arms, but there were no beneficial effects on retinopathy or nephropathy seen at 5 years.

“Some advantages of gastric bypass over sleeve gastrectomy have emerged during follow-up,” Dr. Schauer said. “At 5 years, gastric bypass maintained greater weight loss than sleeve gastrecomy while requiring fewer medications.” He also noted that the final STAMPEDE results might help expand the population of patients in whom bariatric surgery may be considered for improving glycemic control, especially those patients with significant medical problems caused by or made worse by their weight.

“Most clinical guidelines and insurance policies for bariatric surgery limit access to patients with a BMI of 35 or above,” Dr. Schauer added. “Our 5-year results demonstrate that glycemic improvement in patients with a BMI of 27 to 34 is durable at least up to 5 years.” Importantly, he said, patients with a starting BMI < 35 achieved just as much benefit from surgery as patients with a BMI > 35 at study entry.

Congenital heart disease is the most common type of birth defect. Due to advances in treating infants and children with congenital cardiac abnormalities, there is a new challenge: taking care of the growing number of cases of adult congenital heart disease (ACHD), also known as GUCH for grown-up congenital heart disease.

Indeed, for the first time, there is a larger population of adults than kids with congenital heart disease. Currently, there is an estimated 1,000,000 adults with congenital heart disease and 20,000 more patients reach adolescence each year. While many of these individuals had mild congenital defects, more survivors have highly complex heart disease; prevalence increased from 1985 to 2000 and now 49% of individuals born with severe congenital heart disease are adults.

Because many of the advances have been made in the last 2 decades, so far the greatest proportion of individuals with ACHD are still fairly young (mean: 31.7 years). This represents a large wave of individuals who will soon move into the age when ischemic heart disease begins to show up, but their care will be complicated by underlying congenital anomalies.

Unicorns and ‘Naughty Boys’

Jane Somerville, MD, FACC, is a legend in congenital heart disease. She established the first adolescent cardiology ward in 1975 at National Heart Hospital in London. In 1980, she organized the first World Congress of Pediatric Cardiology, also in London. She is called the Mother of GUCH because Dr. Somerville established “Grown Up Congenital Heart Disease” as a subspecialty of cardiology in the United Kingdom and Europe and founded the European Society of Cardiology Working Group on GUCH. The GUCH unit at Brompton Hospital is named after her.

There is no doubt she has trained more fellows in congenital heart disease than any other physician; so much so that a large fan club of ex-fellows called ‘‘the Unicorns’’ gathers at every World Congress of Pediatric Cardiology to celebrate her life and work.

This legend of cardiology is never at a loss for words, certainly not when she recalls the era when she was one of a very small population of female physicians. She refers to “those naughty boys” who did not hesitate to tell her “Jane, you cannot be one of us.” (While “naughty boys” were one challenge, Dr. Somerville noted “girls can be very mean,” too.)

Dr. Somerville recalls, “When I went into medicine, [women] were sort of put to the side, which I found quite amusing. I think women are now taking their place in medicine—they’re 60% of medical school now instead of 9% when I went in. Whether they’ll get to the top is another thing; still lots of naughty boys around.”

She added, “I try to teach my fellows that they have to have imagination. You have to be able to diagnose a disease that you have never seen, or perhaps even read about, and you have to combine your memory with it. That’s why my trainees are called unicorns, because I used to tell them that there’s this imaginary animal that nobody had ever seen but if you saw one in the ward, you’d recognize it. Without the ability to imagine, I’m not sure you would quite know what was going on.”

A Critique from a Legend

Back in 2012, Dr. Somerville felt that, overall, the United States was not providing appropriate care to patients with ACHD. Her opinion has not changed in the subsequent 4 years.

“There are a lot of patients out there who are not being treated and people are having a go at them -- surgeons, physicians, cardiologists -- and it’s a bad reflection on your (US) health service,” said Dr. Somerville. “The first thing you have to do is establish more centers of care. There is no reason to force these patients to live more than half of their lives being badly cared for.”

She continued, “When money is attached to a patient, doctors don’t want to transfer them, they think they know best. Education is being directed at these physicians but a little learning is a dangerous thing, said Alexander Pope, so they are all having a go at them. They go to a course on the topic and they all think they know how to care for these patients.

“Many of (these adult congenital patients) will need to go to special centers,” she continued, “centers offering adult cardiology; these are no longer pediatric patients and they can’t be treated in pediatric hospitals.”

In the United States, the Adult Congenital Heart Association (ACHA) has a directory that currently contains information on 122 ACHD centers in North America. We’re doing a little better since Dr. Somerville’s comments: 17 of those centers have opened since 2012. But again, at least as of ACC.16, Dr. Somerville has seen little improvement in what she views as suboptimal care of these patients in the United States.

‘How Did We Get So Lucky?’

If patients are seeing better care in the UK and elsewhere, Dr. Somerville tries to explain the difference. First, she admits, they established services in the UK with “considerable difficulty” over a period of about 25 years. Money is the critical issue and they got lucky, given the “huge advantage in our national health service being free at the point of entry,” she said. How long that will be the case, she said, is another discussion.

There were obstructions early on to her ideas regarding specialized care, for example, “but we got organized,” she said, and that made a big difference. As she explains it, the government was forced into it by the patient organization that Dr. Somerville inspired and by its leader who understood politics. It is well organized and the centers were deliberately limited due to the number of experts needed to provide optimal care. She is less interested in total number of centers claiming to be specialty centers, but rather she counts well-staffed centers of excellence; by that metric, she counts about 6 such centers in the UK and maybe 9 in the United States.

The UK system is built using a hub-and-spoke design that has a central care facility that branches out and links to other medical centers. With patients “shouting at the Ministry of Health all the time,” Dr. Somerville said, care for ACHD patients is broadly available. The UK is lucky, too, because it is geographically a much smaller area to cover with services. “The lengths of your spokes are very long here,” said Dr. Somerville, “and the geographic problem is very large so you need many more centers. The finances (in the United States) have got to be dealt with.”

Importantly, she said the patients are changing: the grown-up congenital heart disease she is seeing today is a lot different than it was 25 years ago when she was first shouting for attention. The ability to do more perfect surgery and all the imaging available today has made a huge difference, she said.

Read the full November issue of CardioSource WorldNews at ACC.org/CSWN